Seepage is one of the most common hidden dangers in a service process of a water engineering such as a dam, a dike and a sluice, is resulted from complex reasons and is strong in randomness and high in monitoring difficulty, particularly, the damage of more than ⅓ of an earth-rock dam engineering is resulted from seepage and various problems derived from seepage, and it is very possible to result in a serious consequence of engineering outburst if the seepage is not found in time and corresponding rescue measures are not adopted. A great number of engineering practices prove that the enhancement of supervising and monitoring of water engineering seepage is of great significance to guarantee the safe and reliable operation of the engineering. However, most devices, instruments, technologies and the like used for seepage location at present are used with the help of point sensors by which a leak detection phenomenon occurs occasionally, and most traditional seepage sensors have the defects such as large size, great leading wire amount and poor affinity. A distributed optical fiber seepage monitoring technology has obvious advantages on the aspect of avoiding the phenomena, but needs to be assisted by artificial heat/electrical power equipment, has special requirements for sensing optical fibers and is limited by hydraulic engineering characteristics such as severe monitoring environments and hard layout conditions, the monitoring cost of the technology is greatly increased, the monitoring precision of the technology is seriously affected, the popularization of engineering practicability is hindered and constrained, and therefore, a seepage-hidden optical fiber locating device is developed.
For a water engineering such as a river levee, a seawall, a dam and a sluice, seepage hidden dangers occur occasionally under a long-term water load action, and the total quantity of a seepage water body and the behavior of a seepage flow velocity cannot be identified reliably and precisely by using a conventional and direct monitoring means, so that researching an advanced, practical and reliable seepage flow velocity behavior identifying device and method is an important issue attracting great concerns of engineering and academic circles all the time, however, the water engineering body seepage flow velocity monitoring research still stays at a research stage, a lot of problems urgent to be researched and solved on the aspects of a quantitative monitoring theory and an actual engineering layout application still exist, and therefore, it is urgent to develop a seepage flow velocity distributed optical fiber monitoring device which is simple in theory, strong in practicability and convenient to use for a long term based on the water engineering seepage monitoring characteristic and the special working environment.
For the sensing of a dam seepage line, various defects such as low precision, poor anti-electromagnetic interference capacity, incapability of realizing distributed monitoring, short service life, large size, great leading wire amount and poor affinity generally exist in a traditional technology. For a relatively novel optical fiber sensing technology, a maturational distributed optical fiber sensing theory for a seepage line is not established at present, especially, necessary monitoring means and technologies are lacked on the aspects of actual application and popularization, and therefore, it is urgent to develop an online seepage line diagnosis device which is simple in theory, strong in practicability and convenient to use for a long term based on the water engineering seepage monitoring characteristic and the special working environment.
The realization of real-time efficient monitoring of the seepage behavior of the water engineering is of great significance to guarantee the safe service, particularly, the seepage problem of earth-rock particle structures such as earth-rock dams and dikes and influences of the seepage problem are more prominent, it is especially needed that the efficient sensing of the seepage behavior is enhanced and potential safety hazards are found in time, an optical fiber sensing technology serving as an interdisciplinary novel technology receives great attention in the field of safety monitoring of the water engineering due to good mechanical properties and low production cost, however, a lot of problems are to be solved and relieved in the actual engineering application of distributed optical sensing for the seepage behavior of the water engineering due to the specificity such as working environments and structural characteristics, and therefore, a seepage behavior optical fiber self-adaptive identification device which is simple in theory, strong in practicability and convenient to use for a long term is developed.